Planograph co



F. T. ROBERTS.

METHOD or AND APPARATUS FOR MAKING HoLLow RUBBER ARTICLES. APPLICATION FILED JUNE 24. |918.

1,3 10,440. Patented July 22, 1919.

me cnLuMBlA PLANuDAPn co., wAsmNn'roN. D. c.

unirsi) STATES PA'grEN'r OFFICE.

FRED TI'IOMAS ROBERTS, OF CLEVELAND, OHIO, ASSIGNOR TO THE PARAMOUNT RUBBER COMPANY, OF CLEVELAND, OHIO, A CORPORATION 0F OHIO.

Specification of.y Letters Patent.

Patented July 22, 1919.

Application led June 24. 1918. Serial No. 241,405.

To all whom 'it may concern.'

Be it known that I, FRED THOMAS Ro- Enfrs, a citizen of the United States, residing at Cleveland, in the county of Cuyahoga and State of Ohio, have invented a certain new and useful Improvement in Methods of and Apparatus for Makin Hollow Rubber Articles, of which the fo owing is a full, clear, and exact description, reference being had to the accompanying drawings.

This invention relates to the formation of hollow rubber articles having an opening through which an interior form or mandrel may be removed. An object of the invention is to provide a simple, economical process which may effectively accomplish the rapid production of such articles. Still another object is the provision of mold members and like apparatus for advantageously carrying out the process.

My invention is hereinafter more fully described in connection with the accompanying drawings and the essential characteristics are summarized in the claims.

Referring to the drawings, Figure 1 illustrates a plurality of nursing nipples mounted on mandrels which are shown as carried on a single support; Fig. 2 illustrates one of the mold members for forming the article from flat sheets; Fig. 3 is a vertical section taken longitudinally through one of the articles illustrating one of the molds in a position brought to ether over the mandrels; Fig. 4 is a section through the same taken at right angles to Fig. 3; Fig. 5 illustrates one of the mandrels after the article has been removed.

To illustrate this invention conveniently, I have shown a nursing nipple, as an example of an article in the making of which this invention has been found useful. The nipple as shown is of the type having a body portion A, terminating at its open end B and having a contracted neck C, integral with an enlargement in the nature of a readily compresslble spherical bulb D. In forming this article by my process, a comparatively thin sheet of rubber is laid over each of the two mold `lates having registerin cavities surrounde by cutting edges a apted to sever the rubber from the surrounding sheet. The rubber is clamped over the mold cavities by any suitable means and is forced into the cavities by pneumatic pressure. A mandrel having a contour corresponding to the inner surface of the article is then placed in one of the cavities lined with rubber and the molds are brought together to sever the sheet leaving the rubber around the cavit with its meeting edges joined. The mol s may then be separated and the article removed, on the mandrels, and vulcanized while on the mandrels without the use of exterior vulcanizing molds or any confining means fitting the outside of the article.

That the process may be better understood, I will now describe the apparatus illustrated.

Mandrels 1 are shaped to iit the interior of the nipples, and complementary to the surface of the mold cavities but slightly smaller to allow for the thickness of the rubber. The mandrel body has a substantiallyy cylindrical surface at 2, meeting a groove 3 formed in this surface and curved inwardly to a neck portion 4, which carries a substantially spherical member 5, adapted to fit the interior of the bulb B. These mandrels are shown as mounted on pegs 6 secured to a substantially straight bar 8. The bar may carry any desired number of these mandrels whereby they may be conveniently placed simultaneously into a corresponding number of mold cavities and be readily removed with the articles thereon and transferred to a vulcanizing chamber where suitable holders are provided for mounting a large number of such bars and mandrels.

The mold members are indicated at 10, as comprising rectangular body portions carrying integral raised portions 12 in which the cavities 14 are formed. These cavities are adapted to form one half an article so that when registering cavities are brought together, the halves may be united along the meeting edges. To insure the uniting of the edges and to sever the material within the cavities from the surrounding sheet, indicated at S, I provide raised knife edges 15 extending around the cavities from the rooves 16 which form the outer portion of t e bead B. To sever the nipple at its open end from the sheet, I extend this knife at 17 in a semi-circular course substantially at the outer edge of the bead and adapt it to coact with the mandrel just below or outside of the groove 3.

Extending entirely around the edge of the mold plate is a groove 20 which I may term a vacuum clamping groove. Passages 21 leading from th1s groove and communicating withA `a chamber 22 may be exhausted of air by any satisfactory means (connected at the suction opening 25) such as shown, for example, in my prior Patent No. 1,201,502 to draw the rubber into this groove, securely hold it in position and prevent it from vvrinkling as it is drawn into the cavities by the application of vacuum communicated to the cavities 14 through passages 23 and 24. In presenting the rubber sheet to each mold member, it is only necessary to insure a contact of the rubber with the mold plates in such manner as to close the grooves 20 until the vacuum ma be ap plied to the chambers 22 whereby tlie sheet may be held until drawn in the cavities as illustrated in Figs. 3 and 4.

Assuming that the rubber is drawn into the cavities, the mandrels on the bar 8 .are new simultaneously placed into the lower cavities and the mold members then forcibly brought together by the use of any suitable means, such Ifor example, as a hydraulic press. This results in causing the uniting of the rubber sheets at the meeting edges as indicated at E and at the Vsame time causes the knives 17 to force rubber laterally each Way from the knife resulting in fi.lli,n the grooves 3 and 16, thus forming the cad. As these knives 17 meet the surface of the mandrel 1, they complete the severing of the rubber sheet entirely around the nipple. The lmolds may then be separated and the mandrels removed and transferred lto a vulcanizing chamber, While the raw rubbersbreet remaining on the mold plates may be removed and new sheets placed in position to repeat the operation.

After subjecting the nipples to the proper amount of heat to complete Vtheir vulcanization, they Vare preferably removed from the mandrels by turningr them inside out which brings the seam or edge formed by the knives on the inside of the finished .article Winde the exterior of the finished article is that surface formed by the smooth surface of the mandrel.

Itis obvious ythat a comparatively Vlarge number of articles on forming mandrelsfcarried by bars, as described, may beplaced a vuleanizing chamber of given size, resulting in an economy ,of heat which ,is very' marked when compared with the heat Arequired to vulcanize sucharticles ,Wfhen on the inside of heavy metallic vulcanizing molds.

Having thus described my invention, What I claim is: i

1. The method of Vforming hollow rubber articles, consisting of seating rubber stock in cavities in ,two mold members, bringing such rubber lined cavities mtccongunction about a mandrel, severing. thestock andautomatically joining 1t adjacent to edges `of the cavities and also severing thestock transversely against the mandrel.

2. The method of making hollow rubber articlesl consisting of pressing about a mandrel two mold members having cavities in which rubber stock has been seated and having co-acting knife ed es which come together to sever the stoc about a portion of the article, and other knife edges which coact with the mandrel, and thereafter vulcanizing the formed article.

3. The method of making hollow rubber articles, consisting of seating rubber stock in cavities in two mold members, bringing such rubber lined cavities into conjunction about a mandrel, severing the stock and automatically seaming it adjacent to edges of thecavities and also Severin the stock transf versely against the mandre and thereafter vulcanirzing the formed article While on the mandrel.

4. The method of forming a hollow rubber article, consisting of pneumatically seating sheet rubber in each of two coacting mold cavities, brin ing the mold members together (with t e rublbcr seated therein) about a mandrel, and vulcanizing the article while on the mandrel 5. The process of forming a hollow rubber article, consisting of pneumatically seating raw ,rubber stock` in coacting mold cavities, bringing the cavities carrying the rubber together about a mandrel, cutting oi'ln surplus stock .by beveled ribs about the edges of the cavities, and vulcanizing the article, while on the mandrel.

6. The process `of forming a hollow rubber article, consisting of pneumatically seating raw rubber stock in coacting mold cavities, bringin the cavities carrying the rubber together a ut a mandrel, and vulcanizing the article thus tomned on the mandrel without the use of exterior confining means.

7. The process of forming a hollow rubber artiqle, consisting of pneumatically seating rubber stock in coactingfmold cavities, bringing the ,mold members together about a mandrel gtoeause the rubber to unite at its meeting edges and thus form the article about the mandrel, removing the mandrel and subjeoting the article thereon to Vvul-canizing heat, then removing the article from the mandrel., turningthe article inside out.

8. The `process. ci' forming a nursing nipple or like article, consisting of pneumatically seating naw rubber sheets-in mold cavi ties, placing a mandrel in one of such cavi- 'tiesand brlngingithe mold members together to form the article about the mandrel and simultaneously severing the stock fromthe surrounding sheet y'leav71111,.,19;.the article formed on .the mandrel, and vudcanizing the article While en ,the mandrel.

9. The process of vforming a nursing nipple or similar article, consisting of pneu matically forcing rubber sheets in coacting mold cavities, .bringing the mold members together about a mandrel occupying the rubber lined cavities, simultaneously severing the seated rubber from the sheets by coacting knife edges meeting as the molds are brought together and knife edges meeting the mandrel.

10. The process of making a nursing nip ple or sin'ilar article, consisting of .pneumatically forcing raw rubber sheets in coacting mold cavities, bringing the mold members together about a man rel OCCllp'- ing the rubber lined cavities, simultaneous y severing the seated rubber from the sheets by coacting knife edges meetin as the molds are brought together and kni e edges meet-V ing the mandrel, then separating the mold and removing the mandrel with the article thereon, and vulcanizing the article While on the mandrel.

11. The process of forming a nursing nipple or similar article having a bead at its open end, consisting of pneumatically seating rubber stock in the coactin mold cavities, bringing the cavities toget er about a forming mandrel, there being a groove 1n the mandrel and knife edges coacting with the mandrel adjacent such roove which sever the rubber on the man rel from the surrounding stock while at the same time rubberis pressed into the groove to form the bead.

12. The rocess of forming a nursing nip` pleor similar article having a bead at its open end, consisting of pneumatically seating rubber stock in the coacting mold cavities, bringing the cavities together about a forming mandrel having an annular roove, there being knife edges on the mol members about the sides and head of the cavity andconcave knife edges coasting with the mandrel adjacent to its groove, whereby the rubber about the mandrel is severed from the surrounding stock and at the same time a portion of it forced into the groove.

13. The process of making a nursing nipple or similar article having a bead at its Open end, consisting of pneumatically seating raw rubber stock in the coacting mold cavities, bringing the cavities together about a forming mandrel having an annular groove, there being knife edges on the mold members about the sides and head of the cavity and concave knife edges coacting with the mandrel adjacent to its groove, whereby the rubber about the mandrel is severed from the surrounding stock and at the same time a portion of it forced into the groove, and thereafter vulcanizing the article While on the mandrel.

14. A mold for making hollow rubber articles consisting ofl a pair of coacting mold members having registering cavities and a mandrel adapted to occupy7 the cavities, knife edges formed on the mold members about a portion of the cavities and adapted to coact with each other, and other knife edges extending crosswise of the others and adapted to coact with the mandrel.

15. A mold for making hollow rubber articles comprising two coacting mold members, each having registering cavities in the face thereof and each having a beveled cutting rib about the sides and head of the cavity which rib has its edge tangent to the plane of separation of the mold members, other cutting ribs on the mold members ling within the cavities thereof and exten ing transversely, and a mandrel adapted to occupy the cavities when lined with rubber stock and furnish the member against which the transverse cutting ribs act.

16. A mold for making nursing nipples or similar articles, consisting of a pair of coacting members having registering caviY ties, knife edges about the cavities and adapted to meet when the molds are brought together and transverse knife edges corresponding to the end of the nipple, and a mandrel adapted to occupy the mold and coact with the last mentioned knife edges, whereby part of the article may be united at the edges and the whole article severed from the surrounding stock.

17. A mold for making nursing nipples or similar articles consisting of a pair of coasting members having registering cavities, a mandrel adapted to occupy said cavities, an annular groove formed 1n the mandrel, and a transverse knife edge in each of the mold members adapted to sever the rubber adjacent to the groove.

18. A mold for making nursing nipples or similar articles, consisting of a pair of coacting members havin registering cavities, knives about the cavities and adapted to meet when the molds are brought together and knives at the open ends of the cavities correspondin to the end of the nipple, and a mandrel a apted to enter the nipple and coact with the last mentioned knives, said mandrel having an annular groove and the mold members having coperating grooves located adjacent to and parallel with the last mentioned knives.

19. An apparatus for making nursin nipples or similar articles, consisting o mold plates each having a plurality of cavities adapted to register when the plates are brought together, and a plurality of man drels adapted to enter such cavities and carried on a support and spaced correspondingly to the cavities, the mold having passages Whereby stock may be pneumatically seated.

20. The method of making hollow rubber articles closed at one end and open at the other and having a bead about the open end consisting of forming the article about a mandrel having a groove corresponding to lsaid bead and squeezing some of the material into the groove, and thereafter severing the article at the base of the bead.

21. The method of making hollow rubber articles closed at one end and open at the other and having a bead about the open end consisting of forming the article in a mold having a groove on the outside of the article positioned according to said bead, and squeezing some of the material into the groove, and thereafter severing the article at the base of the bead.

The process of making hollow articles consisting of placin sheets of plastic stock across the mouths o? mold cavities, forming sections of the article in finished shape by pneumatically forcing the stock therefor against the walls of the cavities, thereafter bringing the mold members substantially together to press the edge portions of one sheet against the other, a member being interposed between the edges of the sheets, and curing the article while the member is in place.

The process of making a hollow rubber article consisting of pneumatically seating rubber stock in mold cavities, bringing two seated portions into conjunction with Copies of this patent may be obtained for ve cents each, by sudrs'ng'4 the the edges in engagement and upon an interposed mandrel, severing parts of the stock against the mandrel, and thereafter vul` canizing the article with t'he mandrel in it.

24. The method df making hollow rubber articles consisting of pneumatically seating rubber stockV in moldi cavities, lacing a mandrel in one of the cavities ang bringing the two mold members together to join the parts in edge engagement, and thereafter vulcanizirrg the article.

25. The niethod of making hollow rubber articles consisting of pneumatically seating rubber stock in mold cavities, placing a mandrel in one of the cavities and bringing the two mold members together to join the parts in edge en agement, and at the same time shearing o' some of theI stock against the mandrel, then vulcanizing the article while on the mandrel.

26. The process of makin hollow rubber articles comprising pnenma ieal'ly forming the article, cutting' it oit a inst a mandrel, and vulcanizingV 1t with t same mandrel.

In testimony whereof I hereunto ax my signature.

FRED THOMAS ROBERTS.

commissioner 0f ratem's.

Washington, D. 0. 

